ribbons diagrams -- helices are cylinders

please,
one of my colleagues wishes to prepare a ribbons-type figure, with the helices
represented as solid cylinders, instead of open coils (such as in Molscript).
all the programs i'm familiar with, draw helices as open coils. (although we
have MSI's Insight program, we do not have the Biopolymer module, which will
draw cylinder helices.)
does anyone know of another program which will generate ribbon figures, with
cylinders for helices?
marilyn yoder
--
Marilyn Yoder phone: 816-235-1986
School of Biological Sciences fax: 816-235-1503
Division of Cell Biology and Biophysics
University of Missouri-Kansas City e-mail myoder at cctr.umkc.edu
5100 Rockhill Rd
Kansas City, MO 64110-2499